Sensors, Transducers – Motion Sensors - Optical are in stock at DigiKey. Order Now! Sensors, Transducers ship same day An infrared motion sensor has a multi element IR detector with first and second separate arrays of optical elements associated with respective first and second.. A passive infrared sensor (PIR sensor) is an electronic sensor that measures infrared (IR) light radiating from objects in its field of view... PIR motion sensor.. Buy Motion Sensor and get the best deals at the lowest prices on eBay! Great Savings Free Delivery / Collection on many items Everything you ever wanted to know about IR motion sensors Many of the automation systems that increasingly appear in our daily lives have a fundamental..